GMC Yukon XL 2000–2006

▸Known issuesIntake manifold gasket leak (cold idle misfire, lean codes)2

1. Manufacturer communication2002–2004 GMC YUKON XL ・ 2006-04-01(also printed in 8 other issues)

   Rough idle, misfire, MIL with DTC P0300: intake manifold warpage and upper manifold gasket

   1. 1Fault

      • Warning light
      • P0300
      • The condition is rough idle, misfire and MIL with DTC P0300.
      ↓→

   2. 2Finding the cause

      Steps to confirm (in the document’s order)

      • Measure the intake manifold for warpage across two runner ports only.
      ↓→

   3. 3Correction

      Repair

      1. Replace the upper manifold gasket with the teal-green gasket.
      2. The reference given for this row is 05-06-04-029.

      Caution

      • Do not measure the intake manifold across all four intake runner ports.
      • Do not replace the upper intake manifold gasket with an orange gasket.
   Read the sentences of the record

   From the manufacturer’s document

   • Applies to：The row is for 2002-2004 Silverado, Suburban, Tahoe, Sierra, Yukon/XL and Escalade EXT with rough idle, misfire and MIL with DTC P0300.
   • Condition：The condition is rough idle, misfire and MIL with DTC P0300.
   • Confirm：Measure the intake manifold for warpage across two runner ports only.
   • Repair：Replace the upper manifold gasket with the teal-green gasket.
   • Caution：Do not measure the intake manifold across all four intake runner ports.
   • Caution：Do not replace the upper intake manifold gasket with an orange gasket.
   • Repair：The reference given for this row is 05-06-04-029.

   Open this issue of GM TechLink ↗ The points above are read from an article of TechLink, GM’s monthly publication for dealership technicians. The article itself is not reproduced here.

   Remedy

   Truck Issues — Fix It Right the First Time 2002-2004 Silverado, Suburban, Tahoe, Sierra, Yukon/XL, Escalade EXT – Rough Idle, Misfire, MIL DTC P0300 Silverado, Suburban, Tahoe, Sierra, Yukon/XL, Escalade EXT – Rough Idle, Misfire, MIL DTC P0300 Measure intake manifold for warpage across two runner ports only. Replace upper manifold gasket with teal-green gasket. Don’t measure intake manifold across all four intake runner ports. Don’t replace upper intake manifold gasket with orange gasket. Don’t replace upper intake manifold gasket with orange gasket. 05-06-04-029

2. Owner complaint2002 GMC YUKON XL ・ 2006-03-02

   2002 Yukon XL running poorly in cold weather; hard start and no start; intake gaskets and fuel pump issues

   1. 1Fault

      • Does not start
      ↓→

   2. 2Finding the cause

      • Intake Gasket: design or manufacturing
      • Intake Gasket: failed
      • Fuel Pump: failed
      ↓→

   3. 3Correction

      Not stated

      What the documents say to do

      Intake manifold gasket leak (cold idle misfire, lean codes)

      Confirm

      • The seals may leak around the bottom side of the port, which makes the vacuum leak hard to detect.

      Repair

      1. Only the current teal green gaskets should be used; the old gaskets were orange.
      2. The intake bolts must be replaced and not reused.

      Caution

      • Do not measure the intake manifold across all four intake runner ports.
   Read the sentences of the record

   Fault

   ORIGINAL PROBLEM: MY 2002 YUKON XL WAS RUNNING POORLY WHEN THE WEATHER TURNED COLD - BELOW 30 DEGREES. (1 more)

   Cause

   BOTH PROBLEMS ARE BECAUSE THEY WERE DESIGNED FOR USE WITH ETHANOL OR UNLEADED GAS.

   Inspection

   PROBLEM DIAGNOSED AS FAULTY INTAKE GASKETS DUE TO IMPROPER DESIGN. (1 more)